I can't get this stream with NetXFer either. The URL seems to expire too quickly.

Replay Media Catcher can perfectly record from Google Video:
Tutorial: How to record streaming videos from Google Video with Replay Media Catcher

And you can use many other programs that can download/capture/record/save HTTP .flv video streams:
FAQ: How to record/download/capture/save Adobe Flash .FLV video HTTP stream from embedded player